BSN Tracker

ketamine

Brand: Ketalar

⚠ BBW ISMP High Alert Prototype Drug
Drug Class: dissociative anesthetic
Drug Family: anesthetic
Subclass: NMDA receptor antagonist
Organ Systems: cns

Mechanism of Action

Non-competitive NMDA receptor antagonist; blocks the receptor ion channel at the PCP site. Produces dissociative anesthesia: analgesia, amnesia, and trance-like state with preserved airway reflexes. Cardiovascular stimulant (unlike other anesthetics). Rapid antidepressant effects via NMDA antagonism.

NMDA receptormu-opioid receptor (weak)sigma receptor

Indications

  • anesthesia induction (especially hemodynamic instability)
  • procedural analgesia/sedation
  • treatment-resistant depression (esketamine/Spravato)
  • off-label: chronic pain, opioid-sparing analgesia

Contraindications

  • uncontrolled hypertension
  • severe cardiovascular disease where BP increase is harmful

Adverse Effects

Common

  • emergence reactions (dysphoria, hallucinations, vivid dreams)
  • tachycardia
  • hypertension
  • hypersalivation
  • nausea

Serious

  • laryngospasm (rare)
  • respiratory depression at high doses
  • abuse potential (Schedule III)

Pharmacokinetics (ADME)

Absorption IV, IM; intranasal for esketamine
Distribution highly lipophilic; protein binding ~12-27%; rapidly crosses BBB
Metabolism CYP3A4 and CYP2B6 to norketamine (active)
Excretion renal
Half-life 2-3 hours (ketamine)
Onset IV: 30-60 seconds; IM: 3-4 minutes
Peak IV: 1-5 minutes
Duration anesthetic: 10-15 minutes IV
Protein Binding 12-27%
Vd 3 L/kg

Drug Interactions

Drug / Agent Mechanism Severity
benzodiazepines reduce emergence reactions when co-administered beneficial
CNS depressants additive depression; respiratory depression risk at high doses moderate

Nursing Considerations

  1. Administer atropine or glycopyrrolate concurrently to reduce hypersalivation and bronchorrhea.
  2. Keep stimulation minimal during recovery to reduce emergence reactions; calm environment reduces dysphoria.
  3. Midazolam before ketamine markedly reduces emergence dysphoria and is standard practice.
  4. Spravato (esketamine) for treatment-resistant depression requires in-office administration with 2-hour observation; patients cannot drive.

Clinical Pearls

  • Ketamine is the preferred induction agent in hemodynamically compromised patients because it is a cardiovascular stimulant, not a depressant.
  • Ketamine produces rapid antidepressant effects within hours to days via NMDA antagonism, making it the fastest-acting antidepressant known and driving research into glutamatergic depression targets.

Safety Profile

Pregnancy use-with-caution
Lactation use-with-caution
Renal Adjustment Not required
Hepatic Adjustment Required
TDM Not required

Concordance Terms

Cross-referenced clinical concepts — click any term to see all content where it appears.

Anesthesia Induction (especially Hemodynamic Instability) Dissociative Anesthetic Off-label: Chronic Pain, Opioid-sparing Analgesia Procedural Analgesia/sedation Treatment-resistant Depression (esketamine/Spravato)
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